The present invention relates generally to clamps and more specifically to an industrial clamp employing a swinging and linear motion.
Various industrial clamps have an arm which uses a linear and rotary motion. Examples of such conventional devices are disclosed within U.S. Pat. No. 6,059,277 entitled “Retracting Power Clamp” which issued to Sawdon et al. on May 9, 2000, and U.S. Pat. No. 5,165,670 entitled “Retracting Power Clamp” which issued to Sawdon on Nov. 24, 1992. Both of these patents are incorporated by reference herein. Other industrial clamps are known which have a piston rod and an externally mounted arm. The arm is linearly extendable along the piston rod axis and is rotatable only along a transverse plane perpendicular to the piston rod axis. These clamps, known as the 1500 Series and 2500 Series clamps from BTM Corp., are also pneumatically driven with a sealed body. While such traditional devices have significantly improved the art, additional and enhanced movement is often desirable in order to clear workpiece flanges or other obstructions during clamping or unclamping.
In accordance with the present invention, a clamping apparatus is provided that has a body and an elongated member that is extendable from the body. In another aspect of the present invention, a clamp has a workpiece engaging arm mounted adjacent an end of the elongated member. A further aspect of the present invention causes the elongated member to linearly extend and rotate when advanced. In yet another aspect of the present invention, a camming surface is provided in the body of the apparatus. An additional aspect of the present invention provides for improved fastening of the arm to the elongated member. A method of operating the clamp is also disclosed.
The clamp of the present invention is advantageous over conventional devices in that the present invention has an increased and enhanced range of motion during clamping and unclamping in order to clear workpiece flanges and other adjacent obstructions. The present invention is further advantageous by use of an automatically movable opening cover to minimize undesired contamination of the clamp body; this reduces dirt, dust, weld splatter and other external debris from otherwise entering the shaft opening, which could increase friction between moving parts and reduce durability of the clamp. The unique constructions and movement of the present invention cover allow the clamp to remain fully sealed when the workpiece arm is retracted, thereby retaining internal grease and excluding external contaminants. Furthermore, the camming surface design allows for simplified and reduced cost manufacturing and assembly while minimizing body openings that would otherwise need to be sealed. Moreover, the arm-to-shaft mounting arrangement of the present invention provides superior adjustability and fastening. Additional advantages and features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings.